| − | A '''Quadrillion''' in the [[American]] numerical system is a unit of measurement equal to one-thousand trillion. Large number designated by 1 and 15 zeros or 1,000,000,000,000,000 | + | A '''Quadrillion''' in the [[American]] numerical system is a unit of measurement equal to one-thousand trillion. It is designated by 1 and 15 zeros or 1,000,000,000,000,000 |